In 2013 the following happened.....
On July 15, 2013, I made a reservation for a rental car with Nu Car Rentals for the period of December 14, 2013 through December 28 2013.
This was "in cooperation with TRIPLE A Car Rental". The bottom line for this rental was supposed to be $275.52 USD.
When I arrived at the rental office, I was informed that there was a (computer) mistake. The "correct" rate was $480.00 plus taxes and fees for a total of $528.96. The woman behind the counter then took off 15% or $72.00 for a new total of $456.96.
Now while this is slightly different than the situation the OP stated, I think Triple A should stop associating itself with other rental companies.
BTW, I complained to Nu Car rentals and they refunded the difference between the quoted price and the price I ended up paying.